JPS6317908A - Composition curable by ultraviolet ray or electron ray - Google Patents

Abstract

PURPOSE:To provide a composition composed of a specific (meth)acrylic acid ester, a monothiol compound, etc., curable by irradiation of ultraviolet ray or electron ray and giving a cured film soluble in an alkaline aqueous solution without causing the peeling of the film. CONSTITUTION:The objective composition is composed of (A) 80-99.9(wt)% (meth)acrylic acid ester having >=1 carboxyl group and one (meth)acryloyl group in one molecule (e.g. acrylic acid ester oligomer having terminal carboxyl group), (B) 0.1-5% monothiol compound (e.g. octyl mercaptan) and (C) 0-20% compound having one polymerizable double bond in one molecule or its (co)polymer (e.g. N-vinylpyrrolidone, polymethyl methacrylate, etc.). USE:Useful for etching resist ink and film-removing type corrosion-resistant paint, etc.

Description

Detailed Description of the Invention (a) Purpose of the Invention <Industrial Application Field> The present invention is an ultraviolet (hereinafter referred to as UV) or electron beam (hereinafter referred to as EB) curable composition, which In the industrial field, for example, etching resist ink used when creating printed circuits, etc., or paint intended for rust prevention of metals such as iron, film-removal type rust prevention that processes the metal after peeling off the coating. The present invention provides a composition that is useful as a coating material and the like, and the cured products such as a cured resist film and a coating film can be dissolved in an alkaline aqueous solution such as sodium hydroxide and removed as necessary.

〈Prior art〉 Conventionally used coatings, ching resist inks, film-removable anticorrosion paints, etc. can be classified according to the curing method. 2) A solvent-containing composition whose main component is a soluble resin, which is heat-curable.2) A solvent-free composition whose main component is a monofunctional (meth)acrylic acid ester having a carboxyl group, which is UV or EB-curable. It is roughly divided into two types.

UV or EB curable ink has extremely low volatility and UV
It is easily cured by irradiation with EB or EB, and its usage has been rapidly increasing in recent years as a non-polluting paint or ink. Regarding the removal of the cured film, most of the heat curing type mentioned above in 1) are of the solvent dissolving type, whereas most of the UV or EB curing types are of the film removal type. If the film is of a peel-off type, - Since defective products occur due to the peeled film re-adhering to the substrate, measures are taken to remove the peel-off film by installing a screen, etc. Full automation of the device is difficult due to problems such as blockage.

Organic solvents, such as chlorinated organic solvents, and alkaline aqueous solutions are often used to dissolve and remove coatings, but organic solvents pose problems in terms of occupational health and pollution, such as deterioration of the working environment, and are expensive. Even if you think about it, an alkaline aqueous solution is more advantageous.

<Problems to be solved by the present invention> The present invention can be cured by UV or EB, and the cured film can be completely dissolved in an alkaline aqueous solution such as sodium hydroxide, and the cured film can be cured without peeling off. The aim is to provide a composition that can remove .

(b) Structure of the invention <Means for solving the problem> In the present invention, the inventors have discovered that the molecule has one or more carboxyl groups, and one acryloyl group or methacryloyl group [hereinafter referred to as ( Focusing on compositions containing acrylic acid or methacrylic esters (hereinafter referred to as (meth)acrylic esters) as the main component, which have a meth)acryloyl group, we developed a method for removing the cured film by UV or EB irradiation. As a result of intensive studies in order to switch from the conventional film removal type to a completely dissolving type, the main component of this composition, the polymerizable compound, has only one (meth)acryloyl group, but only a small amount of Perhaps because it involves a cross-linking reaction,
Although it was impossible to achieve complete solubility in aqueous alkaline solutions, surprisingly, by adding 0.1 to 5% by weight of a monothiol compound to this composition, the cured film was completely soluble in aqueous alkaline solutions. They discovered that it can be used as a mold, and completed the present invention.

Each component of the composition of the present invention will be explained below.

<Component A> A (meth)acrylic acid ester having one or more carboxyl groups and one (meth)acryloyl group in the molecule,
Total weight of components A, B and C (hereinafter referred to as composition weight)
It must be 80 to 999% by weight based on
Examples of such components include compounds obtained by reacting a compound having one acid anhydride group in the molecule with a (meth)acrylic acid ester having a hydroxyl group in the molecule. Compounds having one acid anhydride group in the molecule may or may not have one or more carboxyl groups in the molecule, and include phthalic anhydride, tetrahydrophthalic anhydride,
Examples include methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, chlorendic anhydride, trimellitic anhydride, etc., and also have a hydroxyl group in the molecule ( As the meth)acrylic acid ester, 2-hydroxyethyl acrylate, 2
Examples include -hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate.

Compounds that can be used as component A are already available on the market, and to illustrate some of them, acrylic acid dimer [rQM-8 manufactured by Rohm and Haas Co., Ltd.
24J) and an acrylic acid ester oligomer containing a terminal carboxyl group (manufactured by Toagosei Chemical Co., Ltd. [Aroex Kai-5300]).

The concentration of component A in the composition of the present invention is 80 to 999% by weight, and if the concentration is lower than 80% by weight, the resulting cured product will be insoluble in an aqueous alkaline solution due to the low concentration of carboxyl groups in the composition. Or, even if it is soluble, it takes time to dissolve, and the object of the present invention cannot be achieved. −
If the concentration exceeds 999% by weight, the concentration of component B will be insufficient, resulting in similarly insufficient solubility of the cured product in aqueous alkali solution. The desired concentration of component A is 90-999% by weight.

<Component B> Improvement in complete dissolution of the cured film in an alkaline aqueous solution is possible by blending a monothiol compound.

Thiols and thioethers are used as chain transfer agents during chain polymerization, and because they can adjust the degree of polymerization without significantly reducing the polymerization rate by adding them in small amounts, they are used as molecular weight regulators. There is.

Various compounds are effective for the above purpose, but when component A is used as the main curable component, the molecular weight of the cured product can be increased by adding a monothiol compound among various chain transfer agents. It has become possible to adjust the material so that it dissolves easily in alkaline aqueous solutions but is resistant to other chemical solutions, such as etching solutions.

Monothiol compounds suitable as component B include mercaptans such as octylmercaptan, nonylmercaptan, decylmercaptan, dodecylmercaptan, and cetylmercaptan, and hydroxyl-substituted mercaptans such as monothioethylene glycol, monothiopropylene glycol, and α-monothioglycerin. Examples include mercaptocarboxylic acids such as , mercaptopropionic acid, 2-mercap, dobtetrapionic acid, thiolactic acid, and thiomalic acid, and the amount added should be 0.1 to 5% by weight based on the weight of the composition. The more preferable addition amount is 0.5 to 3% by weight.

When the concentration of component B is less than 0.1% by weight, the molecular weight of the cured product increases, resulting in poor solubility in aqueous alkaline solutions. If the amount exceeds 5% by weight, the molecular weight of the cured product becomes too low, resulting in poor etching resistance and other physical properties of the cured product, making it impractical.

<Component C> Component C is a component that is optionally blended as a reactive diluent and/or for the purpose of improving the solubility of the cured product in an alkaline aqueous solution.

Examples of compounds having one polymerizable double bond in one molecule include (meth)acrylic acid esters of alkylene oxide adducts of alkyl-substituted phenols (for example, Aroex M-, a product of Toagosei Chemical Industry Co., Ltd.); 101,10
2,111,116,117, etc.), N-vinylpyrrolidone, 2-hydroxy-6-fethoxyprobyl acrylate, and macromonomers. Examples of polymers and copolymers include homopolymers and copolymers of monomers such as vinyl chloride, (meth)acrylic acid esters, styrene, and vinyl acetate; specifically, polymethyl methacrylate , vinyl chloride-vinyl acetate copolymer, rosin-modified maleic acid resin, styrene-maleic acid resin, and the like.

In order to provide a composition that easily dissolves in an alkaline aqueous solution, which is the object of the present invention, the amount of component C should be 20% by weight or less based on the weight of the composition; becomes insoluble in an aqueous alkali solution, and when component C is a polymer, it takes a long time to mix and dissolve in components A and B to prepare a composition.

The preferred amount of component C is 0.1 to 5% by weight, more preferably 0.5 to 3% by weight.

In addition, inorganic fillers such as silica, titanium dioxide, and talc are used to improve hiding power, increase viscosity, increase volume, and impart thixotropy, and pigments are used to improve hiding power and add color. Addition is also possible.

<Curing of composition> A photoinitiator is used when the curing means is UV.

Examples of photoinitiators that are preferably used include Ehahensoin,
Examples include benzoin compounds such as benzoin ethyl ether, benzoin isopropyl ether, penzoin isobutyl ether, penzoin octyl ether, and carbonyl compounds such as benzyl, diacetyl, methylanthraquinone, acetophenone, and benzophenone. The amount of photoinitiator used is 0.01 to 20% by weight, preferably 0.1 to 10% by weight based on the composition of the present invention.
is within the range of

When the curing means is EB, there is no need to use an initiator (because it cures quickly, there is no need to use a curing agent).

These UV and EB irradiation conditions may be in accordance with the conditions commonly used for curing a composition containing a compound having a (meth)acryloyl group as a polymerizable component.

The cured product obtained from the composition of the present invention has, for example, 60 to 90
It is easily dissolved by immersion in an aqueous alkaline solution of sodium hydroxide, potassium hydroxide, etc. with a concentration of 5 to 10% by weight maintained at .degree. C. with stirring. If a cured coating film formed on a substrate is treated under these conditions, the coating film will not peel off from the substrate, but will gradually dissolve from the surface, and will be eluted and removed in a short time within one fraction. .

<Examples, Reference Examples, and Comparative Examples> The present invention will be explained in more detail by showing Examples, Reference Examples, and Comparative Examples below.

(Reference Example 1) Phthalic anhydride 148? , 2-hydroxyethyl acrylate 1221, triethylamine 4.0? , process hydroquinone monomethyl ether 0.135P, air 50
-Heating at 90°C for 4 hours while stirring and blowing at a rate of -7 minutes, phthalic acid monoacryloyloxyethyl ester 265? I got it. Its viscosity was 4500 centipoise at 25°C and its acid value was 205-KOH/P.

(Reference Example 2) Tetrahydrophthalic anhydride 152? , 2-hydroxyethyl acrylate 122F,) ethylamine 4.0?
Tetrahydrophthalic acid monoacryloyloxyethyl ester 269F was obtained in the same manner as in Reference Example 1 except that 0.135 F of hydroquinone monomethyl ether was used. Its viscosity was 13,000 centipoise at 25°C, and its acid value was 199 NgKOH/P.

(Reference Example 3) Phthalic anhydride 148F, 2-hydroxyethyl methacrylate 167? , triethylamine 4.3p, and hydroquinone monomethyl ether 0.140p were used in the same manner as in Reference Example 1 to prepare phthalic acid monomethacryloyloxyethyl ester 281? I got it. Its viscosity is 25℃
4200 centiboise, acid value 1961vKO
It was H/P.

(Example 1) 1 part of mercaptopropionic acid and 5 parts of Irgacure 651 (manufactured by Ciba Gaiki Co., Ltd.) as a photoinitiator were dissolved in 100 parts (parts by weight, same hereinafter) of the ester of Reference Example 1,
A resist ink composition was obtained. This composition was applied to a thickness of about 70 microns on a glass epoxy steel clad laminate (printed wiring board) test panel and irradiated with ultraviolet light. The ultraviolet irradiation device was an ozone-type high-pressure mercury lamp with an input of 80 W/cxi per unit arc length, concentrating the light on a conveyor running 10 m/min below the lamp.
(manufactured by Ushio Inc.) was used. The composition was fully cured by passing it through the device twice. Next, the test panel was immersed in an etching bath maintained at 50° C. for 5 minutes under stirring to dissolve the copper in the unpainted area and washed with water. At this time, no abnormalities such as peeling or blistering were observed in the cured coating film. Furthermore, when the test panel was immersed in a bath of a 5% (wt%) sodium hydroxide aqueous solution kept at 80°C with stirring, the film immediately dissolved without peeling from the cured coating surface, and the 60°C
After a few seconds, the cured coating film was completely dissolved in the IJum aqueous solution. It was confirmed that this composition was completely alkali-soluble.

(Example 2) The same procedure as in Example 1 was carried out except that mercaptopropionic acid was changed to 0.5 part. The composition was completely cured by passing it through the UV irradiator six times. Similarly, after etching, when immersed in a 5% aqueous sodium hydroxide solution at 80°C, the cured coating did not peel off as a film and completely dissolved after 50 seconds.

(Example 3) 90 parts of the ester of Reference Example 1 and aloe and camphorus (Toagosei Chemical Industry ■Product name) M-1021 as a reactive diluent
A composition was prepared in the same manner as in Example 1 except that 0 part was used. The composition was completely cured by passing it through the UV irradiator four times. 5 at 80℃ after etching in the same way.
When immersed in a sodium hydroxide aqueous solution, the cured coating did not peel off as a film (it was completely dissolved after 50 seconds).

(Example 4) Same as Example 1 except that 1 part of mercaptoacetic acid was used.
A composition was prepared. The composition was placed in an ultraviolet irradiation device for 2
It was completely cured by passing it through. Similarly, when the film was immersed in a 5% aqueous sodium hydroxide solution at 80° C. after etching, the cured film did not peel off as a film and completely dissolved after 35 seconds.

(Example 5) Example 1 except that 100 parts of the ester of Reference Example 2 was used.
A composition was prepared in the same manner. The composition was fully cured by passing it through the UV irradiator twice. Similarly, when the film was immersed in a 5% aqueous sodium hydroxide solution at 80° C. after etching, the cured film did not peel off as a film and completely dissolved after 40 seconds.

(Comparative Example 1) A composition was prepared in the same manner as in Example 1, except that mercaptopropionic acid was not used. The composition was completely cured by passing it through the UV irradiator three times. Similarly, after etching, the cured film swelled immediately when it was immersed in an aqueous solution of sodium hydroxide at 80°C, and the film detached from the substrate after 50 seconds.

(c) Effects of the Invention The composition of the present invention is easily cured by UV or EB irradiation, and the cured film is substantially completely dissolved in an alkaline aqueous solution without peeling, and is suitable for printed circuits. It is commonly used as ultraviolet or electron beam curing type etching resist ink used during production, etc., and as a de-modeling rust-preventing paint for the purpose of preventing rust on metal.

Claims (1)

[Claims] 1. Characterized by consisting of the following components A, B and C,
A composition that is cured by irradiation with ultraviolet rays or electron beams to form a cured product that is soluble in aqueous alkaline solutions. A: 80 to 99.9% by weight of acrylic or methacrylic ester having one or more carboxyl group and one acryloyl or methacryloyl group in one molecule. B: Monothiol compound 0.1 to 5% by weight. C: 0 to 20% by weight of one or more components selected from compounds having one polymerizable double bond in one molecule, polymers and copolymers thereof.